This invention relates to a method for the production of fine grain ice or dry clathrate water for manufacturing of concrete/mortar, a method for the production of concrete/mortar by using fine grain ice or dry clathrate water and concrete/mortar products manufactured thereby. Fine grain ice and dry clathrate water for manufacturing of concrete/mortar produced by this invention are used when concrete/mortar is manufactured by use of a small amount of water.
It is possible that concrete/mortar is easily manufactured by making use of fine grain ice or dry clathrate water in places which are difficult to supply with water.
In the case where concrete/mortar is manufactured by a conventional method, much more water is used than the amount of water necessary for hydration of cement in order to uniformly mix and temper cement and water and to keep good flowability as well. However, such method is inconvenient in this method in that strength and durability of concrete/mortar after solidification are lower than the concrete/mortar produced by the use of an amount of water close to theoretical hydration quantity.
For this reason, the technique of mixing cement or cement and aggregate with fine grain ice instead of water has been studied and became known. The features are as follows.
1) Since powder mixture can be performed with cement, mixing can be performed in low water cement ratio.
2) Loss in slump in proportion to the passage of time is small after mixing.
3) The control of temperature for mass concrete can be easily performed.
In the case where this concrete mixing technique is actually applied, however, it is necessary to manufacture fine grain ice and this method is problematic. In a conventional method, fine grain ice is obtained by crushing square ice. In case where fine grain ice is obtained by crushing square ice, the defects are as follows.
1) In case where a large amount of fine grain ice is fed, big plant equipped with special devices such as an ice crusher and a slicer is necessary.
2) Fine grain ice must be kept at low temperature until it is used and an ice storing unit is necessary. Therefore, the control of manufacturing process is troublesome and the cost is high.